Tektronix DPO7054, User Manual

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Analyzing Waveforms
6. View time-domain and frequency-domain
waveforms simultaneously.
Use
Gating to select only a part of
the time-domain waveform for spectral
analysis. (See page 118,
Gating .)
Quick Tips
Sources for spectral math waveforms must be channel or other math waveforms.
Use short record lengths for faster instrument response.
Use long record lengths to lower the noise relative to the signal and increase the frequency resolution.
Different window functions produce different filter response shapes in the spectrum and result in different resolution
bandwidths. See the online help for more information.
The resolution bandwidth (RBW) directly controls the gate width. Therefore, the time domain gate markers move
as you adjust the control.
You can display the linear magnitude of the real data or the imaginary data in the spectrum. This is useful if you process
the spectrum off line and transform it back into a time domain trace.
Using Mask Testing
Serial Communications Mask Testing (Option MTM or MTH) allows you to compare your signal to a predefined template
or mask. For the signal to pass the test, it must fall outside the segments defined by the mask. Generally, standards
committees such as ANSI define the masks. To perform mask testing do the following:
1. Select Mask > Source... .
MSO70000/C, DPO/DSA70000B/C, DPO7000, and MSO/DPO5000 Series User Manual 131